The present invention relates to a printer having an optical printing head for line-by-line recording of picture and text informations and a plurality of juxtaposed, actuatable optical components having picture dot elements which transmit light in dots along the length of a recorded line through objective lenses onto a photosensitive record carrier.
Data processing systems require fast printers so as to convert the electrical input signals into visible displays that can be easily read in a print-out. For this purpose, printers having optical printing heads have been used with success. For example, an optical printing device including a photosensitive record carrier, photopaper or intermediate record carrier and an electrically controllable optical component having picture dot elements to block the flow of light or permit it to pass is disclosed in German Offenlegungsschrift [Laid-open Application] No. 2,557,254.
An optical printer having a magnetically controllable optical component is disclosed in German Offenlegungsschrift No. 2,812,206. It is based on an integrated light modulation matrix which requires neither the deflection of a light beam nor electrostatic charges for the actual printing process. Such an integrated light modulation matrix is disclosed in German Offenlegungsschrift No. 2,606,596.
The operation of that matrix is based on light modulation by means of magneto-optical storage layers, such as, for example, iron garnet layers. Such layers include a uniform arrangement of light switching elements which are switched purely electronically by means of vapor-deposited layers of conductor paths and resistors. With high integration density it is possible to construct line-by-line switching, light switching components having more than one thousand elements. These light switching elements are disposed between a constant light source and a photosensitive record carrier and can be controlled by a character generator in such a manner that the light constantly radiated by the light source can be blocked or passed as required at the locations of predetermined character raster dots.
In order to be able to form a single straight print line on the photosensitive surface, a plurality of light switching elements are required which are arranged in a row transversely to the direction in which the record carrier is transported. Below the light switching elements, between these elements and the record carrier, an optical system is provided for adaptation to the printing surface of the record carrier.
To obtain a precisely aligned printed line without visible transitions between the individual switching elements, adjustment transversely to the optical axis must be possible. For this purpose, one known arrangement adjusts each component composed of one light switching element and one objective lens. Since such a component is relatively large and the displacement must be no more than a few tenths of a millimeter, such adjustment is very time-consuming and costly.